Monday, July 11, 2011

Activity Eight

1. Choose any Teaching Idea from any of the Chemistry Simulations (http://phet.colorado.edu/en/simulations/category/chemistry ) and post your results/data and/or answers on your blog.

I did the balloons and static electricity. Using only one balloon, it picked up the negative charges from the sweater and then when it was put against the wall, it repelled the negative charges. It also went back to the sweater, and was attracted to the positive charges. And then I used two balloons, it didn't really make a difference. They both attracted the negative charges, and once again repelled against the wall and was attracted to the sweater with the positive charges. There was no attraction to each other.

2. Work with any of the Chemistry Simulations to create your own Teaching Idea. The criteria for this is as follows:
a. must identify and meet three (3) science education standards
b. must be original work
c. must be scientifically accurate and appropriate for the directed grade level

Kind of going off of the simulation I did, my teaching idea will be about static electricity and balloons. Using 3 different ballons, one filled with air and another helium, we will do 2 different tests. One will be rubbing against clothes, and the other against each other, then we will place them against a wall and in a bucket of water , as well as putting them up next to each other after the friction is created to see if it repels or attracts to each other.

the science education standards this meets is:
1.When conducting science investigations, ask and answer questions that will help decide the general areas of science being addressed
2. Use the science content being learned to ask questions, plan investigations, make observations, make predictions, and offer explanations
3. When studying a science-related problem, decide what changes over time are occurring or have occurred

This teaching idea is appropriate for elementary and middle school aged children. They will be able to use the balloons and on their own should be able to figure out what they are causing.

Sunday, July 10, 2011

Activity Seven

1. Review the Content Slides Acids and Bases on the D2L site.

2. Complete the Teaching Idea “Concept Questions for Chemistry using PhET”  posted by Trish Loeblein on the pH Scale simulation at PHET (http://phet.colorado.edu/en/simulation/ph-scale). On your blog post the answers with your scientific explanations from the “Clicker Questions pH Scale” posted by Trish.

3. Complete the Teaching Idea “Intro to Strong and Weak Acids and Bases” posted by Chris Bires on the Acid-Base Solutions simulation (http://phet.colorado.edu/en/simulation/acid-base-solutions) and post on your blog your data and answers to the questions posed.


Strong Acid
Weak Acid
Strong Base
Weak Base
Water
pH meter read
(value)
2.00
4.50
12.00
9.50
7.00
pH paper
(color)
red
orange
Dark blue
Dark green
Light orange
Conductivity
(bright/dim/none)
bright
dim
bright
dim
Almost none
Exists as Mostly
(ions/molecules)
molecules
ions
ions
ions
molecules

Strength
Initial Acid Concentration (mol/L)
[HA] (mol/L)
[A-] (mol/L)
[H+] (mol/L)
pH
.010 M
negligable
1.00x10^-2
1.00x10^-2
2.00
.050 M
negligable
4.59x10^-2
4.95x10^-2
1.31
.100 M
negligable
1.00x10^-1
1.00x10^-1
1.00
1.00 M
negligable
1.00x10^0
1.00x10^0
0.00


Strength (approximately)
Initial Acid Concentration (mol/L)
[HA] (mol/L)
[A-] (mol/L)
[H+] (mol/L)
pH
.015 M
1.50x10^-2
3.87x10-5
3.87x10^-5
4.41
.150 M
1.50X10^-1
1.22x10^-4
1.22x10^-4
3.91
.015 M
6.62x10^-4
1.43x10^2
1.43x10^2
1.84
.150 M
negligable
1.50x10^-1
1.50x10^-1
0.82


Strength
Initial Acid Concentration (mol/L)
[MOH] (mol/L)
[M+] (mol/L)
[OH-] (mol/L)
pH
.010 M
negligable
1.00x10^-2
1.00x10^-2
12.00
.050 M
Negligible
1.00x10^-2
1.00x10^-2
12.70
.100 M
Negligible
1.00x10^-1
1.00x10^-1
13.00
1.00 M
Negligible
1.00x10^0
1.00x10^0
14.00


Strength (approximately)
Initial Acid Concentration (mol/L)
[B] (mol/L)
[BH+] (mol/L)
[OH-] (mol/L)
pH
.015 M
1.49x10^-2
1.28x10^-4
1.28x10^-4
10.11
.150 M
1.50x10^-1
4.07x10^-4
4.07x10^-4
10.61
.015 M
1.79x10^-3
1.32x10^-2
1.32x10^-2
12.12
.150 M
6.84x10^-2
8.16x10^-2
8.16x10^-2
12.91


Conclusion Questions:
1.      A strong acid is very concentrated / exists primarily as ions. (circle)
2.      A weak base is a nonelectrolyte / weak electrolyte / strong electrolyte.
3.      A strong base is a nonelectrolyte / weak electrolyte / strong electrolyte.
4.      At the same concentration (Molarity) a strong acid will have a higher / lower / the same pH as a weak acid.
5.      As concentration of a weak acid increases, the pH increases / decreases / remains constant.
6.      As concentration of a weak base increases, the pH increases / decreases / remains constant.
7.      As the concentration of a weak acid increases, the number of ions increases / decreases / remains constant.
8.      As the concentration of a weak acid increases, conductivity increases / decreases / remains constant.
9.      As the strength of a weak acid increases, the proportion of ions to molecules increases / decreases.
10.  As the strength of a weak acid increases, the conductivity increases / decreases / remains constant.